Iridescent material and product



July 5, 1955 s. soBEL 2,712,190

IRIDESCENT MATERIAL AND PRODUCT Filed Ma'y 29,I 1953 KNWU,

IN V EN TOR.

SOL 50BEL ATTORNE)l United States Patent IRIDESCENT MATERIAL AND PRODUCTsoly sober, Plainfield, N. J., assigner to Raiuno-Cei, Inc., PerthAmboy, N. I., a corporation of New Jersey Application Mayz9, 1953,Serial No. 358,301

16 Claims. (Cl. 141-10) This invention relates to iridescent' productsand. is 'concerned more particularly with' the provision of pl'asticproductsV having an iridescent appearance.

It has been proposedy heretofore to impart an iridescent effect tothesurface of wrapping material having a Cellu- Ioid base or to films ofcellulose derivatives or to cellulose papers made transparent by meansof resin or similar materials by applying to such surface a bismuth orantimony compound, and then applying thereover a film of strongly'diluted solutions of. resins or film. formers, e. g. a film of liquidCelluloid. Such materials, although satisfactory as wrapping sheets arenot satisfactory when shredded into akes and an attempt is made toincorporate them into plastics carrier bodies, to make decorative'articles such as costume jewelry, buckles, buttons', studs and thelike, since they quickly lose their iridescent effect. Also, the degreeof iridescence of the wrapping material alone is markedly inferior andlacking in quality. Y Such a teaching is'ex'erripl'ified, for example,by the British patent to Wickel 294,468, of April 1"-8, 1928.'

It has also been proposed to form ornamental obects from plastics byincorporating therein light reflecting particles, such as pearl essence,metal foils, particles of powder, metallic salts, ete. Further, thesebodies have lbeen cut in a 'specific manner, e. g'. so that the lightreflecting particles are oriented in a direction generallyn parallel tothe longraxis of the; body. However, all'such products do not exhibitiridescence, e. g. the 'display of rainbow colors on a surface due tothin films, which cause interference' of light rays,- but rather suchheretofore known products have been referred to as being pearly,nacre-ous, silky, chatoyant,'etc., i. e. lu-sters arising from layers ofreflecting surfaces. Suchateaching isexemplifed by the British patent toMeyer' 548,834, of Aprill 23,v 1941.

lit has further beenx proposed,` an attempt to obtain iridescente'fe'cts in plastics productsto'heterogeneo'usly and indiscriminatelyincorporate cubes, blocks, discs, or

portions of differently pigmented plastics into a plastic mass ofcellulose organic derivative base material on steam-heated kne'adingrolls. Itis important to note that in such prior art suggestionsthestructure of the Hake was obtained by mixing a colloidal suspension ofpearl. essence, mica dust, metallic salts or powders, etc.,.with aplasticizer and then homogeniz'ing the mixture with a. plastics masson`kneading: rolls, the cooled product thereafter bei-ng shredded intoyflakes. Such akes do not exhibit any marked degree of iridescence when.subsequently incorporated into aplastics body; Such a teaehngfi'scontained in the U. S'. patent to Conklin, 2,l54;4'38,l issued on April18, 1939.

I have now determined'that if a polyfilmed flake is incorporated into aplastics base material, wherein the ilakeincludea atleast two metallicfilms, an iridescent product may be formed which will. exhibit the, samedegrec of iridescence as exhibited by the akeitself'.

.Ita is, therefore, one object Aof this invention toprovide aniridescent material which shall haveav greater. decora.- tive effectthan similar products heretofore known. v It 2,712,190 Patented July 5,1955 F. ICC

2 isl another object of this invention to provide an iridescent productcontaining' such material which shall be capable of'greater adaptabilitythan other such products as heretofor'e known and which shall,therefore, be capable of wider use' than heretofore possible. lt is afurther objectiveoflt'his invention to provide products for the costumejewelry industry which shall have an enhanced eye appeal.

Other advantages and objects of my invention will appear from thedescription'thereof hereinafter following:

The invention is illustrated in the accompanying drawings, formin'gpartiof thisspecification, and in which:

'Figure 1 is a cros`ssectional view of the ir'idescentmaterial of myinvention, f l A `Figure 2' isa cro's's-s"ectional view of anotherembodiment of the iridescent material` ofthe invention,

Figure 3' is an elevational View of a part of the' product of theinvention, and p v Figure 4' is an elevational view of anotherembodiment of the' product ofthe invention.

My invention contemplates the provision of 'iridescent material.

Referring to Figure l, the iridescent material has a base layer' 1, ofplastics, and has a first outer layer 2, also of plastics material.Alternatively, the base layer may` have twoy first outer layers, one onveach side' of the base layer. Optionally, a secondf outer layer 3, alsoof' plastics material may` be used', however, vsuchv second outer layermay be omitted', if desired'. Inte'rposed between the base layer 1 andthe first outer layer 2'; and on the surface of the layer 2, or betweenthe layers 2 and 3, are thin metallic films 4v and 5, of the same 'ordifferent materials. It is necessary that' theA outer film4 5 be lighttransmissive, however the inner film 4 may be opaque, if desired. Theseveral layers-may consist of the same or of different plasticsmaterial. ln Figure 2 I have shown a further embodiment wherein fourmetallic films 4, 5, 8 and 9 are employed, interspersed among lay-ers 1,2, 3, 6 and '7. As indicated above,` the outermost layer 7 may beomitted.

The thin metallic films consist of metal and/or metallic compounds. lf ametal compound is used, preferably the salt, then the surface of eachlayer is polished with such metallic' compound.' For example, bismuthoxychlori'de or other halogen `compound-'s of bismuth' or com'-pounds'of other metals may be" used. At least theoutermost metallic filmof the flake mu'st be light transmissive. Also, a pure metal may beused, and it' may be electrodeposited on the plasticslayers or put on byhigh vacuum deposition. v The iridescent efle'c't is obtainedv by theinterference of light reected from the front and the back of the thinfilm, and through the plastic' layers and the metallic 'lrns'therebetween.' `The thickness: of the film determines the colorattributed tol it; thus, as the thickness ofl the' film increases, its'apparent c'ol'or changes analogous toV that of the weil-known Newtonrings; Therefore;y the extremely thin films of the first order arewhite, -yellow or red, while those that are-thicker exhibitapparentcolors that are red, orange, greenish-blue, etc. Where the laminatedmaterial has a plurality of such layers, the thickness may bevariedfrom. layer tola-yer'to produce a variety of iridescenteiects. v f

thermoplastic plastics, the cellulose ethers such as ethyl cellulose,methyl cellulose, benzyl cellulose or cellulose acetate, nitrocellulose,polystyrene, superpolyamides,

acrylate polymers, styrol resins and the like, or combinations thereof,may be used. Of the thermosetting plastics,

phenols or phenol-aldehydes such as phenol formaldehyde or unsaturatedpolyester or alkyd, allyl esters and the like, resorcinols, urans,ureas, silicones, epoxies or combinations thereof may be used.

Figure 3 shows a form of the use of the iridescent material of theinvention. The iridescent material 10, in ,various shapes of flakes,such as discs, thin sheets, triangles, tape, etc., is dispersed througha carrier medium .11, shown as a rod. It is to be understood, however,that the carrier medium may assume any desired physical shape, e. g.umbrella frames, optical frames, etc., or may be supported on any otherbody. In Figure 4, the flake 4material 12 is embedded in a transparentcarrier body 13 in the form of a sphere, which may form a bead fornecklaces, bracelets, etc.

The product may be formed by casting or molding, i. e. iniectioncompression, extrusion, etc. The abovementioned thermosetting plasticsare primarily useful as the carrier body in the case of castings andcompression molding, while extruded products are preferably formed withi the thermoplastic materials. The flake can be employed in all usualmethods of handling thermoplastics, i. e. n

injection molding, laminating, etc.

The following specific examples are illustrative of the presentinvention, but are not to be construed as being limitative ofthe scopethereof.

Example I butyl acetate with a viscosity of approximately .50 poise i at77 F., and the film was coated therewith by immersing it in thesolution. The lm was then withdrawn vertically The film was then atapproximately three inches of movement per minute. f

After the coating had dried and adhered to the cellulose acetate film,it was polished onboth sides with bismuth oxychloride and wiped with aclean cloth to remove any excess powder. The now iridescent material wasthen shredded to a desirable size.

` Example AII- A cellulose nitrate film, approximately .002H thick, wasplaced on a smooth surface. The film was then polished by rubbing onboth sides with a fine cloth whichwas' g with 1% by weight ofbenzoyl'peroxide and heated at dusted with bismuth oxyiodide for suchtime and with such pressure so as to deposit on the surfaceaV highlyreflectant metallic film of a reddish tint.A Then, wiping with a cleancloth, the excess powder was removed. A solution of styrene polymerdissolved in styrene monomer was prepared with aviscosity ofapproximately .SOpoise at 77 F., and the film was coated therewith. byimmersing it in the solution. The lm was then withdrawn vertically atapproximately three inches of movement per minute. cellulose nitratefilm, it was polished with bismuth oxyiodide on both sides, and wiped asabove described. The now iridescent material was then shredded to adesirable size.

Example Ill A polyvinylidene chloride film was placed on a smoothsurface. The sheet was then polished as described in Example I, supra. Asolution of cellulose `acetate dis*- s'olved in methyl Cellosolveacetate with a viscosity of approximately .50 poise at 77 F., wasprepared and the film was coated therewith by immersion. The film wasthen withdrawn and allowed to dry as in the above examples. It was thenpolished again, as described in Example I. A solution of Vinyl butyralwas then prepared and dissolved in a mixture of butyl and methyl alcoholat a viscosity of approximately 80 seconds on a Ford Cup at 77 F., andthe coated lm was immersed in this solution and withdrawn at the rate oftwo inches of movement per minute. When it was dry, it was againrepolished and lwiped as described in Example I. The iridescent materialwas then shredded into flakes.

Example l V A film of aluminum was deposited by high vacuum depositiononto a low volatile regenerated cellulose film. A solution of methylmethacrylate -dissolved in its monomer was prepared at a viscosity ofapproximately '.50 poise at 7.7 F. The regenerated cellulose film wasthen immersed in the acrylic solution and withdrawn as in Example I.When this coating was dry, it was polished, wiped and shredded asdescribed in Example I. Y

Example V Example VI A iilm of silver was deposited by high tracuumdeposition onto a low volatile nylon lm. A solution of cellulose acetatebutyrate was prepared at a viscosity of approximately .50 poise at 77 F.The nylon film was immersed in cellulose acetate butyrate solution andwithdrawn as in Example I. When this coating `was. dry it was polished,wiped and shredded as described in Example I. t

In the last threeexamples, the metallic film may also have been providedby electroplating or flame sprayf ing, etc.

The iridescent material or flake, produced as described in the aboveexamples may be incorporated in a plastics carrier body to form adesired product. vAny plastics material may be used for the carrierbody, such as polyesters, phenolics, ureas, melanines, casein,cellulosics, acrylics, vinyls, etc. The following examples areillustrative of the formation of a product embodying-the iridescentmaterial.

Example V11 Anallyl polyester resinl (e. g. Kriston) was catalyzed about167 F; for about one to two hours until thickening occurred. Such a.plastics material exhibits suficiently high viscosity so that beforethickening occurred a .plurality of iridescent fragments, such asthoseproduced in Example I above, was introduced and the mixture wasAfter the coating had dried, and adhered to the stirred until a yuniform`distribution of flake was obtained. The mixture wasth'en cast into adesired shape, i. e. a rod. Curing takes place after about two hours.

ErampletVlIl V degrees F; i

miami Example IX A properly catalyzed phenolic resin (e. g'.,`Catal'or'1d) was poured into a mold-of a desired' configuration. The flakeswere then added and the mixture in the moldwas thoroughly stirred toobtain uniform distribution. kCuring was obtained at about 175 F. i n

The hereinbefore described specific examples ofthis invention have allillustrated how iridescent flakes and products may be formed.A However,as previously indicated, the scope of.- the invention is not limited "tothe specific metals and plastics mentioned. Thus, for example, anyplastics material maybe substituted for the layers or the carrier bodymaterial mentioned above. Also, any metal or form thereof, may' be usedin any manner, known per se, for forming the lm. v

During the manufacture of the product, care must be taken that theplastics material of the iridescent flake and the plastics material ofthe carrier body are not, at the temperature employed and during theperiod of contact, while the carrier material is soft or fluid, solubleone in the other; since otherwise the sharply defined boundary betweenthe dispersed medium and the carrier body would be destroyed. Therefore,for each type of iridescent flake it is necessary to select a plasticscarrier body of a material compatible therewith, so-'that thetemperature requirements of the carrier body are not in excess of thetemperature limitations of the `iridescent material, so that there is nosolvent or chemical reaction between the two. Furthermore, it isimportant, especially in the case of casting of the thermosettingplastics and monomers, that the fragments or media to be dispersed arefloated into the carrier material while the latter is in such a state ofviscosity that a uniform distribution of the dispersed medium throughoutthe carrier body is possible without settlement thereof during thecuring or hardening of the carrier body.

For molding thermosetting materials, or for molding and extrudingthermoplastic materials, the iridescent particles may be incorporatedwith the molding compound in any suitable manner; for example, onkneading rolls, or in dry mixing with the molding compound, or wherepractical, the iridescent particles may be introduced into the monomer.

TheV transparent carrier body may be backed up, where desired, by anopaque surface, e. g. in the form of a black plastics or an appliedopaque surface. While the specific examples deal with a carrier body andwith flake layers of transparent plastics material, otherlight-transmissive materials, such as translucent plastics or vitreousmaterials may of course also be used. Also, of the layers of the flake,the base or first layer may be of opaque material as long as the outerlayer is light transmissive.

The product of my invention is characterized by a high eye appealthroughout, substantially all of the loosely dispersed fragments orflakes generally participating in the iridescent effect, thus creating asparkling iridescence not heretofore obtained. As illustrative of thefailure of they prior teaching to provide iridescent products comparableto that taught by this invention, the following comparison was made:

Example X A sheet of cellulose acetate film, approximately .002" thick,was polished on one side by rubbing with a fine cloth which was dustedwith bismuth oxychloride for such time and with such pressure so as todeposit on the surface of the sheet a highly reflectant metallic lm. Theexcess powder was then removed by wiping with a clean cloth. The coatedlayer was then immersed in a nitrocellulose solution, and withdrawn asdescribed in Example I, supra. Upon drying, this material was found toexhibit an iridescence. Such material is exemplified in the prior art bythe above-mentioned patent to Wickel. The coated film was then cut intwo and one portion was re- I, supra. oth portions were then' immersedinto a beaker of istyrene monomer. Upon observance it was noted that theportion of thematerial which represented the priorv known teachings lostits iridescent property and merely became Ylight transmissive, whereasthe portion of the material which had the twometallic films, accordingto the teachings of my invention exhibited the same degree ofiridescence as itr had formerly.

Other arrangements of the layers and films of the flake than shown i-nthe drawings and modifications in the product containing. the flakeswill be readily apparent to those skilled in the art and are intended tobe included within the scope of the invention.

This application is a continuation-in-part of my prior filedapplications Serial Numbers 165,398 and 165,399, both filed on June l,1950, now abandoned.

What I claim is: Y

1. An iridescent product consisting of a carrier body at least partiallycomposed of light transmissive plastics material, having dispersedtherethrough a discrete medium of iridescent material in the form of aflake, said flake being characterized as comprising a base layer of asolid material presenting an upper and a lower surface, at least one ofsaid surfaces having thereon a minimum of two metallic films one ofwhich is light transmissive and an interposed layer of a lighttransmissive plastics material therebetween, the layers and films beingso arranged as to have a light transmissive layer and a lighttransmissive film juxtaposed on a surface of the flake, the substancesof the layers, films and carrier body` being so chosen that they do notbecome interfused during manufacture.

2.The iridescent product of claim l wherein the flake has a second lighttransmissive plastics material layer over the outer metallic film.

3. An iridescent product consisting of a carrier body at least partiallycomposed of light transmissive plastics material, having dispersedtherethrough a discrete medium of iridescent material in the form of aflake, said flake being characterized as comprising a base layer of asolid material presenting an upper and alower surface, both of saidsurfaces having thereon a minimum of two metallic films one of which islight transmissive and an interposed layer of a light transmissiveplastics material therebetween, the layers and films being so arrangedas to have a light transmissive layer and a light transmissive filmjuxtaposed on a surface of the flake, the substances of the layers,films and carrier body being so chosen that they do not becomeinterfused during manufacture.

4. The iridescent product of claim 3 wherein the flake has a lighttransmissive plastics material layer over each of said outer metallicfilms.

5. The irridescent product of claim l wherein the base layer is of aplastics material.

6. The iridescent product of claim l wherein the two metallic filmsencompassing the interposed layer are both light transmissive.

7. The iridescent product of claim l wherein the base layer is of lighttransmissive plastics material.

8. An iridescent flake comprising a base layer of a solid material andpresenting an upper and a lower surface, at least one of said surfaceshaving thereon a minimum of two metallic films one of which is lighttransmissive and an interposed layer of a light transmissive plasticsmaterials therebetween, the layers and films being so arranged as tohave a light transmissive layer and a light transmissive film juxtaposedon a surface of the flake, the substances of the layers, films andcarrier body being so chosen that they do not become interfused duringmanufacture.

9. The iridescent flake of claim 8 wherein the flake has a second lighttransmissive plastics material layer over the outer metallic film.

l0. An iridescent flake comprising a base layer of a polished and theexcess removed as described in Example 1I Solid material and presentingan upper and a lower surface, both of said surfaces having thereon aminimum of two metallic films one of which is light'transrnissive and aninterposed layer of a light transmissive plastics material therebetween,the layers and lms being so arranged as to have a light transmissivelayer and alight transmissive'lm juxtaposed on a surface of the flake,the substances of the layers, lms, and carrier body being so chosen thatthey do not become interfused during manufacture. Y

1l. The iridescent flake of claim 10 wherein the flake has a secondlight transmissive plastics material layer over the outer metallic lms.

12. The iridescent ake of claim 8 wherein the solid material of the baselayer is plastics material. i

13. The iridescent ake of claim 12 wherein the two metallic lmsencompassing the interposed layer are both light transmissive. n

:14. The iridescent flake of claim 13 wherein the base layer. is lighttransmissive. l v n A 1S. The iridescent product of claim lwherein theplastics material of the layers isla thermosetting plastic.

16. The iridescent ake of claim 8 wherein the plastics material othe'layers is a thermosetting plastic.

References Cited inthe le of this patent FOREIGN PATENTS Great BritainOct. 27, 1942

1. AN IRIDESCENT PRODUCT CONSISTING OF A CARRIER BODY AT LEAST PARTIALLYCOMPOSED OF LIGHT TRANSMISSIVE PLASTICS MATERIAL, HAVING DISPERSEDTHERETHROUGH A DESCRETE MEDIUM OF IRIDESCENT MATERIAL IN THE FORM OF AFLAKE, SAID FLAKE BEING CHARACTERIZED AS COMPRISING A BASE LAYER OF ASOLID MATERIAL PRESENTING AN UPPER AND A LOWER SURFACE, AT LEAST ONE OFSAID SURFACE HAVING THEREON A MINIMUM OF TWO METALLIC FILMS ONE OF WHICHIS LIGHT TRANSMISSIVE AND AN INTERPOSED LAYER OF A LIGHT TRANSMISSIVEPLASTIC MATERIAL THEREBETWEEN, THE LAYERS AND FILMS BEING SO ARRANGED ASTO HAVE A LIGHT TRANSMISSIVE LAYER AND A LIGHT TRANSMISSIVE FILMJUXTAPOSED ON A SURFACE OF THE FLAKE, THE SUBSTANCES OF THE LAYERS,FILMS AND CARRIER BODY BEING SO CHOSEN THAT THEY DO NOT BECOMEINTERFUSED DURING MANUFACTURE.